150 
HISTORY OF BRITISH CRUSTACEA. 
upwards in this way, it soon regains its liberty. They are 
found on sandy banks, chiefly frequenting those where there 
is a little seaweed. Mr. Bate adds that the larva quits the 
pouch in a form closely resembling that of the parent. He 
has obtained the young of two British species, a Cuma and 
Dlastylis . 
Diastylis Rathkii, Kroyer, sp. (Plate IX. fig. 3.) — 
Alauna rostrata , Goodsir. — When alive, of a beautiful 
bright straw-colour, inclining to yellow. 
Hab. Birth of Borth (Goodsir) ; Moray Birth (Rev. G. 
Gordon) ; Arran, St. Ives (Barlee) ; Balmouth. (Webster) ; 
Plymouth. 
Gen. 5*2. CUMA, Edwards . 
Carapace not produced into a beak in front. Bour seg- 
ments of thorax complete, and exposed behind the carapace. 
Upper antennm single-jointed and scale-like, lower short. 
Abdomen, sixth joint with double-branched stylets. Centre 
tail-piece wanting. 
Cuma scorpioides, Montagu, sp. — When alive, of a fine 
straw-colour, delicately tinged with pink, which is brighter 
in certain lights ; shell rough with shallow fovese. 
